I run into this more often than you would think.
I’ll be working with a controls engineer, or in a manufacturing facility in front of a PanelView Plus or FactoryTalk View SE SCADA system, when I notice the system seems to be running slow.
This sluggishness often has nothing to do with the type of network being used. I’ve seen it happen on RIO as often as I’ve seen it on Ethernet.
The reason for it is almost always caused by a default setting of every new project and display you create within View Studio: The “Maximum Tag Update Rate.”
However, it defaults to a sluggish 1 second update rate.
Now you may think that 1 second isn’t too bad. But when set at 1 second, I typically see a round trip response from “button push” to “on-screen indication” of nearly three seconds.
Why? Well, if you press the button just after the update occurs, you’ll have nearly a whole second go by until it’s read. And once it’s read and sent to the PLC, you’ll then have close to another second until the screen updates again to indicate its on.
Now in my time working with in-plant operators, I’ve come to the conclusion that they feel most comfortable with a response time of one second or less.
If the screen doesn't respond in a second or two, they'll often assume it didn't read their input and press the screen again.
To avoid this, and insure at least a 1 second update rate, I’ve found you’ll need to set each graphic display screen's “Maximum Tag Update Rate” to at lease .25 seconds.
However (if your system has the bandwidth) I would recommend a .1 second update rate as it provides for a very snappy system more in-line with today’s expectations.
Unsure if your EtherNet system can handle these update rates? Check out our previous article on using Rockwell’s Ethernet/IP Capacity tool which can help you quickly benchmark a system.
I hope you've found the above information about speeding up your FactoryTalk View Displays helpful.
If you have a comment, question, or suggestion please feel free to share it with us by filling out the “post a comment or question” link below.
- Thanks for posting an article on this issue. Screen update performance is very important to me.
I am using View Designer with a PanelView 5310 HMI. As far as I can tell the maximum allowed tag update rate it 0.5 seconds - pathetic! This is such a pain point for me that I am considering leaving Allen-Bradley products behind forever. Customers look at my HMIs and tell me they look slow or choppy, and it seems like they assume its because I'm a lazy programmer.
Do you know any way to achieve faster tag update rates in Studio 5000 View Designer as you did with FactoryTalk?Hi! I submitted some other comments, but realized that they aren't true.
You CAN achieve responsive buttons with a PanelView 5310 using a feature called "HMIBC" or HMI Button Control. You get 256 bits of high-speed I/O both to and from the controller, synchronized in under 50 ms! This really saved my neck, so I hope someone else who needs to have a fast tag update rate finds this.Good morning haljonat!
Sorry your comments got stuck in the spam filter - I haven't unboxed the PV5000 that was donated to the blog yet, but it sounds like your solution (HMIBC) is a good one.
Thanks for your comments,
Instructor, The Automation School